LOANS, Amount of Business Lending Loans by Credit Quality Category (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 4,801,375	$ 4,236,206
Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,183,721	3,963,398
Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	617,654	272,808
Business Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,497,271	1,262,484
Business Lending [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,233,628	1,124,594
Business Lending [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	263,643	137,890
Business Lending [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,267,738	1,043,470
Business Lending [Member] | Pass [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,048,364	949,960
Business Lending [Member] | Pass [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	219,374	93,510
Business Lending [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	144,775	121,214
Business Lending [Member] | Special Mention [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	124,768	103,176
Business Lending [Member] | Special Mention [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	20,007	18,038
Business Lending [Member] | Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	77,144	92,488
Business Lending [Member] | Classified [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	60,181	71,458
Business Lending [Member] | Classified [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	16,963	21,030
Business Lending [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	315	0
Business Lending [Member] | Doubtful [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	315	0
Business Lending [Member] | Doubtful [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Business Lending [Member] | Acquired Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,299	5,312
Business Lending [Member] | Acquired Impaired [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Business Lending [Member] | Acquired Impaired [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,299	5,312
All Other Loans [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,950,093	2,838,804
All Other Loans [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	354,011	134,918
All Other Loans [Member] | Performing [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,934,994	2,820,941
All Other Loans [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	351,880	132,074
All Other Loans [Member] | Nonperforming [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,099	17,863
All Other Loans [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,131	2,844
Consumer Mortgage [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,581,458	1,544,401
Consumer Mortgage [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	188,296	68,983
Consumer Mortgage [Member] | Performing [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,568,653	1,529,035
Consumer Mortgage [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	186,506	66,629
Consumer Mortgage [Member] | Nonperforming [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,805	15,366
Consumer Mortgage [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,790	2,354
Consumer Indirect [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	890,339	832,745
Consumer Indirect [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	45,421	1,223
Consumer Indirect [Member] | Performing [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	890,237	832,653
Consumer Indirect [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	45,421	1,223
Consumer Indirect [Member] | Nonperforming [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	102	92
Consumer Indirect [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Consumer Direct [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	178,051	178,585
Consumer Direct [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	17,025	5,443
Consumer Direct [Member] | Performing [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	177,999	178,547
Consumer Direct [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	17,011	5,425
Consumer Direct [Member] | Nonperforming [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	52	38
Consumer Direct [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	14	18
Home Equity [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	300,245	283,073
Home Equity [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	103,269	59,269
Home Equity [Member] | Performing [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	298,105	280,706
Home Equity [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	102,942	58,797
Home Equity [Member] | Nonperforming [Member] | Legacy Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,140	2,367
Home Equity [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 327	$ 472